<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>
    *{
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }
    .p1{
      font-size: 20px;
      text-align: center;
    }
    .div1{
      width: 300px;
      height: 300px;
      background-color: salmon;
      margin: auto;
      position: relative;
    }
    .span1{
      font-size: 30px;
      display: block;
      width: 100px;
      background-color: seagreen;
      margin: auto;
      text-align: center;
    }
    .div2{
      width: 70px;
      height: 70px;
      background-color: violet;
      position: absolute;
      /* left: 50%;
      margin-left: -35px; */
      transform: translateX(115px);
      bottom: 50%;
      margin-bottom: -35px;
    }
  </style>
</head>
<body>
  <p class="p1">段落</p>
  <div class="div1"><div class="div2"></div></div>
  <span class="span1">111</span>
</body>
</html>